Reliability analysis of wind-excited structures

Abstract

The structural effects induced by the wind constitute a stochastic process which depends, in turn, on the wind, the structure and the aerodynamic parameters. Structural verifications usually consider statistical moments of the process, such as the mean maximum or standard deviation, or its maximum value. Since the estimate of the parameters is uncertain, all these quantities should be treated as random. Therefore, the evaluation of the full distribution of the effect is often prohibitive to calculate. This paper studies the probabilistic response of wind-excited structures and carries out reliability analyses with respect to a limit state of a generalized wind load effect. When the effect considered is a deterministic quantity, the structural safety is studied applying, straightforward, simplified procedures. When the effect is a random variable, recourse is made to a suitable expression which separates the uncertainties due to the parameters of the calculation model and the inherent randomness of the wind load effect. In this way, an approximate description of the probability distribution of the response is given, suitable for reliability analyses. Neither the precision of the procedure, nor the numerical burden seems much affected by the number of random variables involved.